1. Field of the Invention
The present invention relates generally to systems and methods for testing neuropsychological dysfunction and, more particularly, to systems and methods for diagnosing neuropsychological dysfunction that employ computer simulated environments.
2. Description of the Related Art
Continuing medical and technological advances have resulted in more prematurely born infants living than ever before, and current research has shown that 25% of those infants carry mild to moderate disabilities. In addition, there are large numbers of young adults who suffer brain damage and cognitive dysfunctions caused by head injuries. It is estimated that more than seven million children between the ages of six and twenty-one, and approximately twenty million adults over twenty-one have either mental retardation, learning disabilities, or traumatic brain injuries with attendant cognitive deficits. One category of cognitive deficits are known as executive dysfunctioning.
Executive Functions are those functions which significantly determine the extent to which a person exhibits appropriate and responsible adult behavior. They enable individuals to establish priorities, make decisions, or alter a course of action when intervening circumstances require action modifications. Of the cognitive defects that impact daily functioning of people with neurological deficits, executive functions effect the everyday personal, interpersonal, and work related behaviors in ways that critically impact interpersonal relationships and functional abilities in the areas of independent living and work.
Four major components of executive functioning are volition, planning, purposeful behavior and effective performance.
Volition is an individual""s will, agency, choice, etc., that emanates from knowing what one wants and contains the motivation to gratify those wants and desires.
Planning reflects one""s ability to plan and execute a sequential series of goal directed behaviors. Competent planning demonstrates skills in organizing, thoughts and plans, securing and working with the necessary people, equipment, tools, etc. Effective planning also requires mental flexibility when unexpected obstacles intervene.
Purposeful behavior reflects the ability to initiate purposeful sequentially executed behaviors that demonstrate awareness of self, others, and the environment. It involves the person""s capacity to employ flexibility when circumstances require modifications in goal and adoption plans.
Effective performance indicates the capacity to observe, correct, and regulate one""s own behavior, affect speed of operation, and thoroughness of performance. Attitude and judgment or performance thoroughness are important to observe and assess. (Lezak, 1995, PP 650-677).
Disorders of executive functioning can be reflected by inadequate self care skills, in (difficulty managing) or spending money prudently, and problems initiating and completing intentional, goal-directed, self monitoring actions. There is typically evidence of all or some of the following deficiencies:
1. Problems with volition and initiating behavior can be reflected by a lack of motivation, the inability to initiate intentional actions, and may involve difficulties in executing and sustaining focused, goal-directed actions. There often is a lack of self awareness and sensitivity towards others.
A person is aware of the need to shower, brush teeth, comb hair and wear clean clothes, but is unable to do this regularly unless another person remains present and directs each step of the morning hygiene and personal care routine.
A man""s inability to stop flooding every new girl friend with gifts, invitations and phone calls results in his inevitably losing every newly initiated relationship. The man always experiences sorrow and remorse for causing the woman enough distress to break-up with him. However, regardless of the guidance or reminders of behavioral rules, the man can not refrain from resorting to the same behaviors when starting out with a new girlfriend.
2. Planning deficits are often related to poorly organized action sequences that include the necessary people and resources to reach the intended goal. The insufficient awareness of the relationship between planning, actions and outcome poses problems when these individuals are confronted with the unanticipated repercussions of their poor planning and inability to implement alternative strategies.
A woman wants to complete her college education. She registers for courses that are too demanding and beyond her academic skills. She is unable to attend classes, maintain part time employment, and she refuses any advice and suggestions from college counselors or professionals. Their recommendation that fewer and less demanding courses be considered is ignored and the woman drops out of school, blaming her failures on the teachers and xe2x80x9csystem.xe2x80x9d
A person wants to live in his own apartment and xe2x80x9crun his own life.xe2x80x9d However, he makes no attempt to earn a steady job which would enable him to afford an apartment and the self maintenance expenses. While he sees the relationship between wanting an apartment, needing the money to pay rent, and getting a regular paying job, he makes no independent attempt to look for a job or contact a vocational rehabilitation agency.
3. Inability to execute purposeful behaviors is characteristically reflected in impulsive actions disinhibited speech and/or conduct where the person is unable to contain irrelevant or reflexive responses. Difficulties also occur when routinely executed functions no longer are appropriate and the person cannot modify his plan or behavior according to those changes (Levinson, 1996).
A young clerical employee talks with his financial tutor about taking a week""s vacation to Disney World. He wants to travel by airplane, stay in a hotel, and visit the park. Discussions reveal neither an awareness of the planning process, nor a realistic idea of the involved costs. His desire to contact airlines, hotels, and the park without assistance were initially respected. A lack of results led the counselor and the employee into developing a written money saving and planning process. With frequent case-manager visits, he was able to follow the written directions.
4. Ineffective performance refers to the difficulty a person has observing, modifying and regulating his/her behavior.
A man with average intelligence receives financial counseling regarding budgeting, bill paying, managing his check book and use of funds for leisure activities and life essentials. Despite agreed upon strategies and guidelines geared to help the person live within his financial boundaries, he usually cashes pay checks immediately and spends seventy-five percent of his earnings despite bills, obligations and other expenses which require attention.
5. Perseverations are behaviors or verbalizations which, driven by internal, unconscious and/or neurological determinants, continue well beyond interpersonal and/or circumstantial appropriateness.
A person with cognitive disabilities is taught how to greet guests who come to the door. However, once he introduces himself, asks the person""s name, and says xe2x80x9cpleased to meet youxe2x80x9d he persists in going through the script long after it is applicable. (This behavior also may reflect impulsivity.)
6. Impulsive behaviors are those that occur without regard to contextual or social appropriateness without regard for consequences.
A person living from a fixed income and budget goes food shopping. He brings his shopping list and the usual amount of money. While selecting items from this list he is approached by a promoter to purchase a manual food processor on a ten day, fully refundable trial. The person makes the purchase, is unable to complete the necessary food purchases and blames the independent living instructor for not having him bring sufficient funds. (Also, inadequate planning and self monitoring may contribute.)
7. Diminished self and interpersonal awareness exists when a person is unaware of how his/her behavior impacts another person, is (in)appropriate to the context and demonstrates little self awareness as well as reduced capacity to alter behavior or acknowledge it.
A person applies for and interviews for a job. During the meeting, the applicant admonishes the interviewer for being late. When job duties are described the applicant complains that there is too much time required filling in as a receptionist. The applicant did not notice the interviewer check and re-check his watch, cross his arms, and interrupt the applicant mid sentence when the applicant scorned the salary. Later when asked how the interview proceeded, the candidate disclaimed any interest in the job, saying that the salary and hours weren""t worth it.
8. Inability to switch conceptual frameworks refers to an individual""s difficulty shifting attention from one feature of the environment to another. With impaired executive functioning, an individual finds it difficult to respond in optimal ways. For example, successful employment and social relationships require the ability to recognize and respond to feedback, the ability to control impulses, and a certain amount of cognitive flexibility. Obviously, assessment and rehabilitation techniques that most closely reflect the real world will prove most beneficial to the millions of individuals suffering from cognitive and neurological dysfunction.
As these examples show, a person with executive dysfunction may outwardly appear to function with normal skills, but have dysfunctions which manifest during everyday routines. Diagnosing these dysfunctions is problematic for the very reason that they are often not observable from a typical lab testing situation. A person may function perfectly during analysis and review of activities. It is only when they are engaged in daily activities that these dysfunctions appear.
Attempting to determine executive dysfunctions from observing the person during daily situations is problematic. First, there is the time and expense of accompanying and observing the person during their daily routines. Such observation may take several days or weeks to readily determine a pattern of executive dsyfunctions. Further, the presence of the observer can affect the results, wherein the person will modify their behavior or take different actions because they know the observer is there. For dysfunctional persons attempting to autonomously function in the real world, the presence of an observer is a self-conscious reminder to behave xe2x80x9ccorrectlyxe2x80x9d. Further, when a support person is present, the dysfunctional individual can defer to them for advice instead of making their own decisions.
Accordingly, the present invention includes a system and method for testing a subject for determining neuropsychological dysfunctions, including executive dysfunctions, using computer simulated reality to provide more accurate assessments of a subject""s executive deficits. The illustrative embodiments of the present invention include a predetermined test scenario script, to provide a test scenario to the subject. A scenario simulation component on the computer, produces a simulated reality environment based on said predetermined test scenario script, which is displayed to the subject using visual systems such as monitors and head mounted displays (HMDs).
The subject interacts and responds to the environment by various input devices including keyboards, joysticks, pointing devices, tactile and sensory gloves, etc. A test scenario result reviewing component, accepts the input from the subject in response to the subject interacting with the simulated reality environment, and determines result information based on analyzing the subject""s interactions. The result information includes processing by standard techniques, including statistical analysis, to determine a score.
The system also accepts, as input, physiological measurements from the subject.
The scenarios provide more ecologically valid scenes that simulate real life situations and will identify and predict, with greater applicability to real life, validity and reliability, executive functioning disabilities and their likely impact on daily living activities. Dysfunctions such as, for example, difficulties in correctly identifying categories of sorting, perseverative responses, inability to shift concepts/sets, etc., are analyzed and identified to determine the existence and significance of any deficits in executive functioning.
Advantages of the present invention include an objective, repeatable test standard for gauging individuals and measuring results. Computer simulations allow standardized tests to be presented to individuals, allowing comparison of results. The results are more valid and reliable than existing paper and pencil tests that are administered by different examiners, and scored by different interpreters. The measured results, obtained in accordance with the present disclosure, demonstrate the nature and extent of the cognitive disabilities. Further, the results translate, because of their ecological validity, more easily into rehabilitation training (whether by Virtual Realty (VR) xe2x80x9csessionsxe2x80x9d or other methods) and transfer into real world environments.
Moreover, a fully developed test scenario is low in cost to administer. Actors and props are not necessary to enact situations for observing a test subject""s reactions.
Another advantage of the present invention is a xe2x80x9csafexe2x80x9d environment for test subjects to interact in real-world situations without harm or loss of money. Test parameters such as background noise can be readily adjusted to requirements for the test subject. Further, since the test subject is typically limited in the movement they can perform during the test, it is easy to monitor the test subject including physiological measurement instruments, such as, for example, blood pressure, EEG, EKG, galvanic skin sensors, eye, hand movement, etc.
In one particular embodiment, in accordance with the present disclosure, a system for testing neuropsychological dysfunction is provided which includes at least one predetermined test scenario and an interactive computer generated simulated environment, based on the predetermined test scenario. A test scenario processor communicates with the interactive computer generated simulated environment and is configured to receive input from a subject interacting with the interactive computer generated simulated environment in order to determine a neuropsychological dysfunction diagnosis of the subject. The input received from the subject may include physiological measurements.
In an alternate embodiment, the system includes a test administrator input which communicates with the test scenario processor. The test scenario processor receives input from a test administrator for modification of the predetermined test scenario.
The interactive computer generated simulated environment may provide at least one question to the subject based on the predetermined test scenario. The question may be modified by the test administrator. The interactive computer generated simulated environment may provide a plurality of questions. Modification may include omission of a portion of the plurality of questions. Further, the system may include a plurality of predetermined test scenarios in which the test administrator may substitute portions of the plurality of test scenarios.
The interactive computer generated simulated environment can include a plurality of questions based on the predetermined test scenario. The test administrator may modify the plurality of questions when the subject""s input includes perseverations. The system can also include a plurality of predetermined test scenarios.
In an alternative embodiment, the predetermined test scenario includes a sequence of real life events. In this embodiment, the interactive computer generated simulated environment includes at least one question to the subject based on the sequence of real live events. The sequence of real life events may include a beach scene.
The predetermined test scenario may include a sequence of non-reality events whereby the interactive computer generated simulated environment includes at least one question posed to the subject based on the sequence of non-reality events.
In another alternative embodiment, interactive computer generated simulated environment may be substantially immersive. The interactive computer generated simulated environment may, alternatively, be substantially non-immersive.
A method for testing neuropsychological dysfunction is provided in accordance with the present disclosure. The method comprises the steps of providing at least one predetermined test scenario; producing an interactive computer generated simulated environment based on the predetermined test scenario; interacting the interactive computer generated simulated environment with a subject; receiving input from the subject interacting with the interactive computer generated simulated environment by a test scenario processor communicating with the interactive computer generated simulated reality environment; and determining a neuropsychological dysfunction diagnosis of the subject based on the input received by the test scenario processor.
The method may include the step of producing an interactive computer generated simulated environment which is substantially immersive. Alternatively, the method may include a step of producing a computer generated simulated environment which is substantially non-immersive.
The method may include a step of receiving input from a test administrator for modifying the predetermined test scenario. Further, the step may include a predetermined test scenario which has a sequence of real life events. The interactive computer generated simulated environment may include a plurality of questions to the subject based on the sequence of real life events. In addition, the sequence of real life events may be based on a beach scene.